This invention relates to improvements in a known type of latch assembly for sliding building closures such as sliding glass doors or windows. Heretofore, such devices mounted in the upper track for sliding doors have been provided with a stop member elongated in a direction parallel to the track and pivoted about a transverse horizontal axis so that a door-abutting portion of the stop member moves vertically between an upper retracted position and a lower door-abutting position in the path of the door. Vertical movement of the opposite or tail end of the stop member is limited in order to limit the downward movement of the door-abutting portion to establish its door-abutting position.
The improvements contemplated by the present invention pertain to the means for pivotally supporting the stop member, the inclusion of a shoulder means in addition to the pivot means for preventing forcible longitudinal movement of the stop member toward the tail portion, and a particular arrangement whereby such a latch assembly abuts a projection attached to an outer door which rides in a track which is exposed to the exterior when the door is in its closed position. The invention also deals with spacer means which prevents unauthorized vertical movement of the door.
Unlike previous devices, the pivot means is connected to the track on both sides of the stop member. A stationary shoulder is positioned adjacent to the tail portion of the stop member when the tail portion is in its uppermost position, thereby resisting forcible movement of the stop member in a direction toward the tail portion. Further, in the case of an outer door which moves in a track exposed to the outside when the door is in its closed position, a projection is affixed to the inside of the door for coaction with the stop member which is movable from an upper position removed from the path of the projection to a lower position located in the path of the projection.
It is well known that sliding closures may be removed by lifting them vertically to move them into the upper track and permit their disengagement from a lower track or guideway, thus enabling an unauthorized entrant to remove the entire closure and gain ingress through the doorway. Unauthorized entries of this type are prevented by providing spacer means in the upper track. Such spacer means may be both a portion of the latch assembly itself and separate spacer blocks attached to the track. The blocks are constructed so that their horizontal and vertical dimensions are unequal when measured in a plane perpendicular to the tracks, and spacer plates are attached thereto in order to provide a wide variety of thicknesses in the block-and-spacer assembly to position it proximate to the upper surface of the door.
For a more complete understanding of the invention in its preferred form, reference is made to the accompanying drawings and the following description of the preferred embodiments.